The present-invention generally relates to a flat screen display devices consisting of with a-network of transistors, and the systems for workshop adjustment of the video images displayed therein.
Flat screen devices are increasingly being used in motor vehicles in order to display not only indications of vehicle driving conditions but also more elaborate information such as a roadmap or films, for example, requiring a good display quality of the video images.
So-called thin-film technologies known by the abbreviation TFT are employed in order to produce them or alternatively the screens consisting of a network of thin-film transistors TFT.
TFT screens are controlled and driven by electronic control circuits which prepare and transmit video image signals to be displayed in a predetermined format any may take into account parameters which modify the display quality and to compensate for the manufacturing tolerances. These parameters are, for example: luminosity, contrast, flicker, etc. It is workshop adjustment, or pre-adjustment, which makes it possible to fix their initial values.
Most of the means for pre-adjusting flat screen display devices currently comprise a reticle generator for displaying images making it possible to identify the defects due to poor adjustment of the aforementioned parameters. Displaying the generated reticles on the screen makes it possible to manually adjust the value of these parameters by utilizing potentiometers provided in the electronic control circuits.
These manual operations can be time-consuming, expensive and give rise to poor homogeneity of the devices upon leaving the workshop. Furthermore, the parameters adjusted in this way are not constant over time.